Delayed arming device for projectiles



Aug, 23, 194% J. F; MCCASLIN ET AL. I 9

DELAYED ARMING DEVICE FOR PROJECTILES Filed May 6, 1947 5 Sheets-Sheet l JAMEEEM EASLIN,

JEAN PINK,

Aug. 23, 1949- J. F. MccAsLlN ET AL DELAYED ARMING DEVICE FOR PROJECTILES 3 Sheets-Sheet 3 Filed May 6, 1947 4&3

Kr 2g I gvwQ/Mbd! JAMEE PZM EAELIN, A56 JEAN FINK, $5 93141 i atented Aug. 23, i94

UNlTED STATES ,m si

2,479,851 DELAYEQ ABMING Davids Foe PROJECTILES v corporation of Delaware Application May "6, 1947', semi No. 746,298

' Ibis invention relates to delay arming device's forming of the booster charge of a jeetile fuse and which are interposed between the fuse and booster charge to prevent a premature detonation oi the latter upon premature funetlonirig of the former. I I I object of the mvehti'on is to provide a delay arming device which is an improvement over that disclosed in the coepending application of ,iame sR 'Mocaslin, Serial No. 588,879, filed Apr-ii 111 1945, now Paterit Number 2,446,545, granted Au ust, 10, 948! I 1 A further object is to provide a pivotalunit including a gear train and escapeinent wherein the. eseapement is normally positioned on the axis of rotation of the projectile. I I

A further object is to providea dr'h'ving weight for a device; or the character which exerts a com stant torque on the driven parts, I

A further object is to provide a delay arming device including a roton a primer carried by the rotor, and means for holding said rotor immobile with, the primer in a disarmed position jihtil the completion of the delay cycle and means there= upon operative to release said rotor for movemen: to position said primer in an armed posh tl'on- I A further object is to provide a delay arming device such as that last described which includes swingable means engaging said rotor to prevent rotation thereof, latch means engaging said To.- tor to prevent rotation and a portion f said swlngable means normally engaghig said latch prevent release or the same from said rotor tuitil the end of the arming cycle said swlngable means being operative to relieve said latoh from torque pressure of said rotor duringthe arming cycle.

A. further object is to provide a 'delayaiming device including mechanism for moving aprimer into an armed position at the close of an armiiig cycle, a cover plate having an aperture therethrough for passage of a; firing pin, and overlap ping movable portions of said mechanism closing said hole at all times prior to the armingof said device. I

Other objects and advantages reside the particular form of the invention, in the combine tion and arrangement of the several parts thereof and in the particular method.- or mode of operatioii, alt of which will be readily apparent to those skilled in the art upon reference to the drawing" and specification wherein the invention tsshowmdescribediand claimed.

mlthezdrawlna 13 Glaims. (Ci. 1U 2'"79) Fiefire i is a plan vie ten-tr snowing the cover plate in position and the parts the unarmed position. I Fig iii' 2 is 'a View like Figure; 1 with the i lt l ifi L Y 'Fi'g ur 3 is a viewnke Figure 2 but showing the parts in the armed position.

Figure 4 is avertioa'l section on the :piane of theme a- =4 of Figure 2. I f F'igure 5 is a horizontal section taken on the mane of the line 5"''i-5 or Figilre 4. I I

, Figure 6 ma h r z ntal section taken on the blaiie of the line'tifi of Figure 4.

vfl ig ur e '7 is" a View like Figure 2 but showing amo dificatioh or the invention. a I I I I Figure 8 is a view like Figure 7 but showing the parts in the armed position; and I Figure 9 is a nagisenraryvemem section take orijthe plane of line 9:9 of Figure :7. I Referring specifically to 1-6 inclusive, It esignate -a casing" for one form of our inventiofi, Sachs-aging is of cup-like form and the open. end thereof is mterhally and externally threade at I] and I2 for engagement with the rose and shell respectivelt not shown. B'eio'w the internal threaas H, the casing 10 isi'ormed with a redu ed and irregular recess l3 which nr vide at its upper edge a shoulder 14' for the cover plate IS. The cover plate .15 "is centrally apertured, at 1.6 for the passage. of the firing pin, not shown; and is further provided with a pluralityof tires-mam disposed holes to receive positioniilg pins, vjoi zot birds. and, the like "including fastening means I1. I

The delay arming nichafiism li's' seated'iilvariolispartsof the recess 13 and comprises a "rotor 2 0, a latch 30, a welglitd driving' leve'i 4,9? and a svv ilzlgablegeartrain assembly 53, all or "which will be describedin; detail hereinafter.

Rotor tit pivotea at. 21' eccentric to the ax s Qtcasing lfl 'and is ,forn'id with an arm 22 through is fort fied an aperture seating a primer 23;. Qpposite thev rm 22,1311 rotor '21) is ziornred toprolvic'le a fan-shaped eccentric weight; 214 whereby centrifugal ,force generated E3 the. rotation or the shell after firing tends to rotate the rotor in 'a counterclockwise Vdiie'ctio'r'i. A; portion of the upper; surface or the weight 24 cutaway to provide a recess 2 5 to receive and confine the free' end of the swingalol sea-i trait; assembly when the mechanism is the unarmed position (Fig. 2). A marg nal edge the recess 25 is formec1- to,.proiiide a notes 23 toreceivethe inne1j d6g'L' 33} or tlifeT latch 30, and iurt'her recessed to provide a. bevelled snow der 21 to seat the weighted driving lever 40. A stop pin 28 is provided in the cavity I3 to limit the movement of the rotor in both directions. When the rotor is in the unarmed position, the primer 23 is positioned out of alignment with the flame hole 29 which extends through the floor of and is located on the axis of the casing I0. When the rotor is in the armed position, the primer is aligned with such flame hole.

The latch 30 comprises a generally arcuate centrifugally actuated lever one end of which is pivoted to the casing I at 3|. A weight 32 is formed on the upper surface of the latch 30 adjacent the free end thereof and serves the dual purpose of acentuating the centrifugal force actuating the lever and also serves as an auxiliary support for the gear assembly 50 during setback. (Fig. 4.) The free end of the latch lever 30 is formed to provide inner and outer dogs 33 and .34? respectively. The inner dog 33 is adapted to seat in the notch 26 of the rotor 20 when the latter is in the unarmed position to prevent rotation thereof. The outer dog 34 bears against the rounded portion of the pivot 5| of the gear assembly 50 to maintain the latch in looking relation to the notch 26 of the rotor 20. When the pivot shaft 5! has been rotated a predetermined distance, as will be described later, the flat portion 52 clears the dog 34 and permits centrifugal force to swing the latch radially outward to release the dog 33 from the notch 26 of the rotor 20.

The driving lever 40 is generally arcuate in form and is pivoted at one end as at M to the casing I0. A driving weight 42 is formed on the driving lever adjacent the free end thereof for accentuating the centrifugal force generated by the rotation of the shell in flight and which causes the driving lever to swing radially outward. The free end of the driving lever is formed to provide a segmental gear 43. When the driving lever 40 is in the unarmed position (Figs. 2 and 6), it bears against the bevelled shoulder 21 of the rotor 20 and the radially outermost of the teeth of gear 43 are in driving engagement with a pinion 53 of the pivotal shaft 5I of the gear train assembly 50. Thus, as the driving lever 40 is swung outwardly by centrifugal force, the segmental gear 43 rotates the pinion 52 and the pivotal shaft 5|.

The gear train assembly case 50 comprises a generally arcuate casing one end of which is pivotally connected to the casing I0 by the pivotal shaft 5I. The gear case 50 contains any suitable reduction gearing which is adapted to be driven by rotation of shaft 5| and which drives anescape wheel 54 rotation of which is regulated by an escapement 55 (Figs. 1, 2, 3). For the purpose of clarity, the gear train within the case 50 has not been shown as no particular'reduction gearing is claimed herein. When the gear case is in the unarmed position (Figs. 1, 2), the free end bears against a side wall of the recess 25 of the rotor 20 so as to assist in preventing rotation thereof and to relieve the latch dog 33 of part of the torque pressure of the rotor 20. With the gear case 50 in the unarmed position (Figs. 2 and 4), the free end thereof is positioned in alignment with the flame hole 29 of the casing I0 and forms an added safeguard against premature detonation of the shell. The escapement 55 is then positioned, as shown, on the axis of rotation of the casing I0. I

In operation, when the shell is fired a rapid rotation is imparted thereto by the lands and grooves of the gun barrel. Such rotation gener- 4 ates a centrifugal torque in each of the parts 20, 30, 40 and 50, but the parts 20, 30 and 50 are temporarily prevented from reacting to such torque by the various latching devices. However, the driving lever 40 is not latched and immediately commences to swing in a clockwise direction on its pivot 4|. At the same time the segmental gear 43 of drive lever 40 begins to rotate the pinion 53, shaft BI, and the reduction gears contained in the case 50. The case 50 remains stationary as it is confined in the recess 25 of rotor 20. The length of time, and the consequent delay in the arming time, consumed in the passage of the segmental gear 43 past the pinion 53 depends upon the number of teeth on said gears and the particular arrangement of speed reduction gears in the case 50 and is unimportant for the purposes of this invention. However, it is important that the segmental gear 43 clear the pinion immediately after the positioning of the flattened part 52 of shaft 5| at a point to clear the outer dog 34 of the latch 30, whereby centrifugal force swings the latch 30 out of engagement with the rotor notch 26 just before the segmental gear 43 clears the pinion 53 and frees the gear case 50 for centrifugally actuated swinging movement out of engagement with the shoulder of the recess 25 of the rotor 20. Centrifugal force thereafter causesthe rotor to swing in a counterclockwise direction until stopped by stop pin 28, at which position the primer 23 is aligned with the flame hole 29 and the mechanism is armed. Centrifugal force thereafter maintains the parts in the armed position. In the event that it is found to be desirable to incorporate positive means for maintaining the parts in the armed position, any well known automatic means (not shown) for accomplishing this purpose may be incorporated into the device.

The modification of Figs. 7, 8, 9, is generally similar to the form of the invention of Figs. 1-6 inclusive, and comprises a casing I00 having'a flame hole I29 extending axially thereof through the floor of an irregular recess II3 therein. As

= in the first described form of the invention the delay mechanism comprises a rotor I20, latch :23, driving lever I40 and reduction gear case The rotor I20 is pivotally mounted at ,I2I for rotation in the recess I I3 and mounts the primer I23. A recess I is formed in the upper'surface of the weighted end I24 of the rotor and pro vides an abutment I21 at one side thereof which seats the free end of the gear case I50 when the parts are in-the unarmed position (Fig. 7). A marginal edge of the recess I25 is formed to pro: vide a notch I26 to receive the latch dog I33 of the latch I30.. I '7 The latch I30 is pivoted to the casing I00at I3I and is provided at its free end with the latch dog I33 on the inner edge thereof. The outer edge I34 of the free end of the latch is concave in form and concentrically engages the circular edge of a latch disc I56 which is fixed on the pivot shaft I5I of the gear case I50. Such ell-.- gagement of the disc I56 and the latch I30 main tains the latter in latching engagement with the rotor I20.

The driving lever I is pivoted to the casing I00 at MI and the free end thereof is formed to provide a segmental gear I43 which, in the une armed position is in engagement with the pinion I53 of the gear case I50. Suitable weights (not shown) may be added to latch I30 and driving sneaked lever IEO to correspond to weights '32 and 42o? the first described form of the invention.

The gear case I50 is pivoted to the casing I tion of the pivot shaft 151 andwhichis regulated by the escape wheel 154 and escapement 155. The latch disc I56 is fixed on shaft and is cut away at one side to provide a concave recess I52 The curve defining su'ch recess i52 substantially corresponds to the arc described by the free end of the latch I3 5 whereby to permit disengagement of the latter from the rotor IZll when, rota tion of the shaft l5] has progressed sufficiently to position an initial portion of said recess I52 in alignment with the free end edge ofsuch'la'tch. As in the first described form of theinvention, this event occurs just before the segmental gear M3 clears the drive pinion I53 so that the hear-- ing of the free end of the gear case 150 against the abutment L21 of the rotor is maintained for a split second after the latch disengages to facilitate the latter operation. F

It should be noted thatin both forms of the invention, the torque generated in 'thegearjcases 50 and 550 by the rotation of the drive pinions 53 and I53 is in a direction to urge the free ends of the gear cases in directions to resist the torque of the rotors.

The structures of both forms of the invention have similar advantages which include a driving lever exerting a constant torque; theescapements positioned ,on the axis of rotation of the shell whereby the centrifugal force generated in night exerts little or no forcejonthe escapement during the operation of the delay mechanism; the rotors are retained in the unarmed position until the arming points are reached by the combined locking functions of the latch and gear case; and the swingable -feature of the gear case enables it to close the firing pin opening IS in the cover plate |-5 until the armingpoint is reached, thereby providing an additional safeguard against premature detonation. It should be noted also, that in both forms of the invention the shapeof the recessesili and 125 in the rotor is such that they confine the free end of the gear cases therein to prevent premature or accidental swinging of the same-to theJarmed position.

While we have shown and described what are now thought to bathe preferred forms of our-invention, it is to be understood that the same is susceptible of other forms and expressions. Consequently, we do not limit ourselves to the precise structures shown and described except as hereinafter claimed.

We claim:

1. A delay arming mechanism for a projectile, comprising a casing, having an axial flame hole therethrough, a rotor eccentrically mounted in said casing for centrifugally actuated movement from an unarmed to an armed position, a latch pivotally mounted in said casing and engageable with said rotor for locking the same in an unarmed position, a gear case including a drive pinion, a gear train driven thereby and an escapement regulating said drive, said gear case being swingably mounted in said casing for centrifugally actuated movement from an unarmed to an armed position, said escapement being positioned on the axis of rotation of said casing in the unarmed position, a recess in said rotor receiving said gear case in the unarmed position and holding the same in said position, a centrifugally actuated drive lever pivotally mounted in said casing and including a segmental gear on the free end thereof in Working engagement with said drive pinion when the mechanism is in the unarmed position-said segmental ear being operative to rotate said pinion and actuate said gear train upon swinging of said drive lever, means associated with said pinion and engaging said latch to hold the same in latching relation to said rotor throughout the greater portion of the r0.- tation of said pinion and thereafter releasing said latch for disengagement from said rotor, said segment gear thereafter clearing said pinion to release said-gear case for centrifugally actuated movement out of engagement with said rotor to permit centrifugally actuated movement of said rotor to the armed position.

'2. The structure-of claim 1, a pivot shaft pivotally mounted in said casing and having said pinion fixed thereon, said shaft being notched at one side thereof, said shaft comprising said meansengaging latch, and said notched portion being adapted to register with said latch upon partial rotation of said shaft to rel-ease said latch for disengagement from said rotor.

3. The structure of claim 1, a pivot shaft mounting said pinion, said shaft being pivotally mounted in said casing, a disc fixed on said shaft adjacent said pinion, a concave recess in one edge of said disc, the rounded portion of said disc comprising said means engaging said latch, and said concave recess being adapted to register with said latch upon partial rotation of said shaft to release said latch for disengagement from said rotor. r

4. A delay arming mechanism for a projectile, comprising a casing, an axial flame hole therethrough, primer means mounted in said casing for centrifugally actuated movement from an unarmed position to an armed position in alignment with said flame hole, a gear case pivotally mounted in said casing, a delay arm ng gear train and an'escap-ement in said gear case, centrifugally' operated means for actuating said gear train, said escapement being positioned over and across said flame hole when in "unarmed position to close said flame hole, said gear case being pivoted to clear said flame hole upon completion of the arming cycle.

5. A centrifugally operated delay arming mechanism for a projectile, comprising a casing, a primer carrying rotor pivoted in said casing, a pivoted latch for locking said rotor in an unarmed position, a pivotally mounted delay gear train in said casing and including means engaging said latch to hold the same in a latching position during the arming cycle, means on said rotor engaging said gear train to hold the same in an unarmed position during the arming cycle, and centrifugally actuated means for actuating said gear train to provide the arming cycle and to release successively said latch, rotor and gear train for centrifugally actuated movement to armed positions at the completion of said arming cycle.

6. The structure of claim 5, an escapement on said gear train, and said escapement being positioned on the axis of rotation of said projectile during the arming cycle.

'7. In a centrifugally operated delay arming mechanism for a projectile, a generally cylindrical casing having a first central axis of rotation, a centrifugally operated rotor pivoted in said casing on a second axis radially onset in one direction from said central axis; a gear case, an escapement and gear drive therefor in said gear, case, means journaling said gear case in said casing for pivotal movement as a unit on a third axis radially offset from said central axis in a direction opposite to said one direction, centrifugally operated means for driving said gear train and escapement in response to rotation of said mechanism on said central axis, latch means normally holding said rotor and gear case in unarmed inwardly-pivoted positions, and means responsive to driving of said escapement for releasing said latch means to free said rotor and gear case, said rotor and gear case then pivoting outwardly away from said central axis in generally opposite directions.

8. In a centriiugally operated delay arming mechanism for a projectile, a casing having an end wall, a central axis of rotation and a flame hole in said wall, a gear case pivoted in said casing on an axis ofiset from said central axis, a gear train and escapement carried by said gear case, latch means normally holding said gear case in an unarmed position over said hole, means centrifugally responsive to rotation of said mechanism about said central axis to drive said gear train and escapement, and means responsive to a predetermined operation of said gear train and escapement to release said latch means and permit centrifugal movement of said gear case to an armed position clear of said hole.

9. A centrifugally operated delay arming mechanism for a projectile comprising a casing having a central axis of rotation, a closed end wall and a flame hole through said wall, an escapement and driving gear assembly pivoted in said casing for movement as a unit about an axis offset from said central axis, holding means including a centrifugally operated latch for holding said assembly in unarmed position closing said hole, means responsive to centrifugal force created by rotation of said mechanism on said central axis for driving said gear and escapement assembly, and means responsive to a predetermined operation of said escapement to release said holding means and permit centrifugal pivotal movement of said assembly to armed position clear of said hole.

10. A mechanism as recited in claim 9, said holding means including a rotor journaled in said 5 casing and having a primer moved into alignment with said hole as said rotor pivots from a first unarmed position to a second armed posi- 8 tion, therebeing a recess in the periphery'of said rotor in which the free end of said assembly fits when said assembly and rotor are in their respective unarmed positions.

11. In a centrifugally operated delay arming 'mechanism for a projectile, a casing having a closed end, a central axis of rotation and a flame 'hole in said end substantially on said axis, a rotor pivoted in said casing on' an axis radially offset in one direction from said central aXis, an escapement and driving gear assembly pivoted in said casing on an axis radially offset in the opposite direction,-said rotor and assembly when in unarmed ;position being superposed over said hole, latch means holding said rotor and assembly in unarmed position, means responsive to rotation of said. mechanism for driving .said escapement, and means responsive to a predetermineddegree of driving of said escapement to releasesaid latch 'means whereby said rotor and assembly are pivoted radially outward in opposite directions to arm said mechanism.

' 12..In a centrifugally operated delay arming mechanism for a projectile, a casing having an end wall, a central axis of rotation and a flame hole in said wallin substantial alignment with said central axis, a gear case pivoted in said casing on an axis offset from said central axis, a geartrain and escapement carried by said gear case, latch means normally holding said gear case in a first position over said hole, centrifugally-operated means to drive said gear train and escapement, and means responsive to a predetermined operation of said gear train and escapement torelease said latch means and release said gear case'f'or movement to an armed position clear of said flame hole.

, '13. The mechanism recited in claim 12, said escapement being substantially on said central axis when said gear case is in unarmed position.

JAMES F. MCCASLIN. JEAN FINK.

REFERENCES CITED The following references are of record in the file of this patent:

7 g I v UNITED STATES PATENTS Number i 

